The Vatican arrested a Spanish priest and a laywoman suspected of stealing confidential documents and leaking them to the media, the Holy See acknowledged Monday.

The two, who served on a special commission that Pope Francis established to advise him on economic and administrative reforms at the Curia, were arrested and interrogated over the weekend, according to a statement. They were identified as Spanish priest Lucio Angel Vallejo Balda and public relations expert Francesca Chaouqui.

The monsignor, 54, holds one of the top positions in the Vatican's economic affairs office. He's being detained in a Vatican City jail cell, a Vatican spokesman told the Associated Press.

Chaouqui, 33, was released Monday after she agreed to cooperate with the probe. She has retained one of Italy’s top criminal attorneys, Giulia Bongiorno, who’d secured an acquittal for American Amanda Knox's co-defendant in an internationally watched murder trial, the AP noted.

The panel last year finished its work and submitted a report to the pope, who subsequently implemented reforms including setting up a new economic ministry, according to Reuters.

Leaks constitute crime

Based on a law enacted early in Francis’ papacy, "the leaking of confidential information and documents is a crime,'' the Vatican said in a statement.

Vallejo Balda belongs to a priest group linked to Opus Dei, the conservative Catholic organization. "If the allegation [against him] turns out to be proven, it will be particularly painful because of the damage done to the church," the AP reported Opus Dei as saying in a statement.

Last week, Vatican police were investigating tampering of a computer used by Libero Milone, the Holy See’s top auditor appointed several months ago, the AP reported, citing Italian news reports. The Vatican confirmed the tampering probe but didn’t say whether the arrests of Vallejo Balda and Chaouqui were linked.

French news agency AFP noted the incident represents the Vatican’s second leak scandal in three years. The butler to Pope Benedict XVI, Paolo Gabriele, was convicted in 2012 of stealing the now-emeritus pontiff’s private papers and leaking them to a journalist. Gabriele, pardoned by Benedict after he served several months in a Vatican jail, now works in a Vatican-run hospital, Reuters reported.

Books on Vatican due out

Books by two Italian journalists, containing new evidence on past Vatican scandals, are scheduled for release on Wednesday.

One is "Merchants in the Temple," by Gianluigi Nuzzi. It follows up on his 2012 book, "His Holiness," based on documents provided by Gabriele.

Fittipaldi writes for L'Espresso newsweekly, which, the AP points out, "has published some of the most damaging leaks of Francis' papacy, including most recently the letter by 13 cardinals warning Francis about his family synod."

Some material for this report came from AFP, the Associated Press and Reuters.